The Sphere-o-Bot Boss[1] is the Master Robot of Aqua Planet Zone in Sonic Chaos. It is an odd, egg-shaped robot built by Dr. Robotnik, and is the fifth boss of the game.


When the player comes to the wide area at the end of Aqua Planet Zone Act 3, the first phase of the battle starts with numerous Mecha Hiyoko Badniks moving from the right as charging to the player. The player can easily destroy them by Spin Jumping on them. After that, the second phase then starts up with the Sphere-o-Bot Boss itself falling to the arena and it then starts bouncing around the area while shooting small energy projectile at a time, similar to the Bouncy Boss Robot. The player has to avoid being crushed, while also dodging projectiles. The battle may take a long time, as the player has to hit the Sphere-o-Bot Boss to its last legs in order to progress the final phase of the battle.

After this happens, the Sphere-o-Bot Boss starts exploding and raises to the air. It will then removes its upper part of the body and launches numerous Mecha Hiyoko Badniks as missiles as trying to the player down. These Badnik missiles fly everywhere, while the player has to dodge all of them at all cost. After this, the lower part of the Sphere-o-Bot Boss appears again above and shoots another set of Badnik missiles. If the player is fast enough, he/she can deal the final hit into the Sphere-o-Bot Boss, thus ending the battle. If the player is not fast enough, he/she has to try again after another missile shower. After eleven hits on Master System or seventeen hits on Game Gear, the Sphere-o-Bot Boss is destroyed and the player moves to the next Zone.


  • The Sphere-o-Bot Boss was originally unnamed in the Master System manual; however, in a Sonic The Comic Q Zone that covered it, it was alternatively dubbed The Egg With The Deadly Centre![2]
  • The Sphere-o-Bot Boss is unnamed in Japanese sources, and does not have any accompanying artwork.
  • The Sphere-o-Bot Boss is similar to Goose Mecha from the 8-bit version of Sonic the Hedgehog 2, as both of them utilize smaller Mecha Hiyoko Badniks during the battle.
  • During Aqua Planet Zone Act 3, there are Invincible video monitor on the lower pathway. However, it does not take long to be used when the player arrives at the boss arena, even if the player uses lower, secret pathway.
    • There is also Super Ring monitor at the linear, upper pathway, that only Tails is able to get.




  1. Sonic Chaos (Game Gear) United States instruction manual, pg. 15.
  2. Sonic the Comic #26, "Sonic Chaos Part 4 - The Bosses"
Community content is available under CC-BY-SA unless otherwise noted.